(function() {
    var lastTime = 0;
    var vendors = ['webkit', 'moz'];
    for (var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) { window.requestAnimationFrame = window[vendors[x] + 'RequestAnimationFrame'];
        window.cancelAnimationFrame = window[vendors[x] + 'CancelAnimationFrame'] || window[vendors[x] + 'CancelRequestAnimationFrame']; }
    if (!window.requestAnimationFrame)
        window.requestAnimationFrame = function(callback, element) { var currTime = new Date().getTime(); var timeToCall = Math.max(0, 16 - (currTime - lastTime)); var id = window.setTimeout(function() { callback(currTime + timeToCall); }, timeToCall);
            lastTime = currTime + timeToCall; return id; };
    if (!window.cancelAnimationFrame)
        window.cancelAnimationFrame = function(id) { clearTimeout(id); };
}());
(function($) {
    $.snowfall = function(element, options) {
        var defaults = { flakeCount: 35, flakeColor: '#ffffff', flakePosition: 'absolute', flakeIndex: 999999, minSize: 1, maxSize: 2, minSpeed: 1, maxSpeed: 5, round: false, shadow: false, collection: false, collectionHeight: 40, deviceorientation: false },
            options = $.extend(defaults, options),
            random = function random(min, max) { return Math.round(min + Math.random() * (max - min)); };
        $(element).data("snowfall", this);

        function Flake(_x, _y, _size, _speed, _id) {
            this.id = _id;
            this.x = _x;
            this.y = _y;
            this.size = _size;
            this.speed = _speed;
            this.step = 0;
            this.stepSize = random(1, 10) / 100;
            if (options.collection) { this.target = canvasCollection[random(0, canvasCollection.length - 1)]; }
            var flakeMarkup = null;
            if (options.image) { flakeMarkup = $(document.createElement("img"));
                flakeMarkup[0].src = options.image; } else { flakeMarkup = $(document.createElement("div"));
                flakeMarkup.css({ 'background': options.flakeColor }); }
            flakeMarkup.attr({ 'class': 'snowfall-flakes', 'id': 'flake-' + this.id }).css({ 'width': this.size, 'height': this.size, 'position': options.flakePosition, 'top': this.y, 'left': this.x, 'fontSize': 0, 'zIndex': options.flakeIndex });
            if ($(element).get(0).tagName === $(document).get(0).tagName) { $('body').append(flakeMarkup);
                element = $('body'); } else { $(element).append(flakeMarkup); }
            this.element = document.getElementById('flake-' + this.id);
            this.update = function() {
                this.y += this.speed;
                if (this.y > (elHeight) - (this.size + 6)) { this.reset(); }
                this.element.style.top = this.y + 'px';
                this.element.style.left = this.x + 'px';
                this.step += this.stepSize;
                if (doRatio === false) { this.x += Math.cos(this.step); } else { this.x += (doRatio + Math.cos(this.step)); }
                if (options.collection) {
                    if (this.x > this.target.x && this.x < this.target.width + this.target.x && this.y > this.target.y && this.y < this.target.height + this.target.y) {
                        var ctx = this.target.element.getContext("2d"),
                            curX = this.x - this.target.x,
                            curY = this.y - this.target.y,
                            colData = this.target.colData;
                        if (colData[parseInt(curX)][parseInt(curY + this.speed + this.size)] !== undefined || curY + this.speed + this.size > this.target.height) {
                            if (curY + this.speed + this.size > this.target.height) {
                                while (curY + this.speed + this.size > this.target.height && this.speed > 0) { this.speed *= .5; }
                                ctx.fillStyle = "#fff";
                                if (colData[parseInt(curX)][parseInt(curY + this.speed + this.size)] == undefined) { colData[parseInt(curX)][parseInt(curY + this.speed + this.size)] = 1;
                                    ctx.fillRect(curX, (curY) + this.speed + this.size, this.size, this.size); } else { colData[parseInt(curX)][parseInt(curY + this.speed)] = 1;
                                    ctx.fillRect(curX, curY + this.speed, this.size, this.size); }
                                this.reset();
                            } else { this.speed = 1;
                                this.stepSize = 0; if (parseInt(curX) + 1 < this.target.width && colData[parseInt(curX) + 1][parseInt(curY) + 1] == undefined) { this.x++; } else if (parseInt(curX) - 1 > 0 && colData[parseInt(curX) - 1][parseInt(curY) + 1] == undefined) { this.x--; } else { ctx.fillStyle = "#fff";
                                    ctx.fillRect(curX, curY, this.size, this.size);
                                    colData[parseInt(curX)][parseInt(curY)] = 1;
                                    this.reset(); } }
                        }
                    }
                }
                if (this.x > (elWidth) - widthOffset || this.x < widthOffset) { this.reset(); }
            }
            this.reset = function() { this.y = 0;
                this.x = random(widthOffset, elWidth - widthOffset);
                this.stepSize = random(1, 10) / 100;
                this.size = random((options.minSize * 100), (options.maxSize * 100)) / 100;
                this.speed = random(options.minSpeed, options.maxSpeed); }
        } //素材家园 - www.sucaijiayuan.com
        var flakes = [],
            flakeId = 0,
            i = 0,
            elHeight = $(element).height(),
            elWidth = $(element).width(),
            widthOffset = 0,
            snowTimeout = 0;
        if (options.collection !== false) {
            var testElem = document.createElement('canvas');
            if (!!(testElem.getContext && testElem.getContext('2d'))) {
                var canvasCollection = [],
                    elements = $(options.collection),
                    collectionHeight = options.collectionHeight;
                for (var i = 0; i < elements.length; i++) {
                    var bounds = elements[i].getBoundingClientRect(),
                        canvas = document.createElement('canvas'),
                        collisionData = [];
                    if (bounds.top - collectionHeight > 0) {
                        document.body.appendChild(canvas);
                        canvas.style.position = options.flakePosition;
                        canvas.height = collectionHeight;
                        canvas.width = bounds.width;
                        canvas.style.left = bounds.left + 'px';
                        canvas.style.top = bounds.top - collectionHeight + 'px';
                        for (var w = 0; w < bounds.width; w++) { collisionData[w] = []; }
                        canvasCollection.push({ element: canvas, x: bounds.left, y: bounds.top - collectionHeight, width: bounds.width, height: collectionHeight, colData: collisionData });
                    }
                }
            } else { options.collection = false; }
        }
        if ($(element).get(0).tagName === $(document).get(0).tagName) { widthOffset = 25; }
        $(window).bind("resize", function() { elHeight = $(element)[0].clientHeight;
            elWidth = $(element)[0].offsetWidth; });
        for (i = 0; i < options.flakeCount; i += 1) { flakeId = flakes.length;
            flakes.push(new Flake(random(widthOffset, elWidth - widthOffset), random(0, elHeight), random((options.minSize * 100), (options.maxSize * 100)) / 100, random(options.minSpeed, options.maxSpeed), flakeId)); }
        if (options.round) { $('.snowfall-flakes').css({ '-moz-border-radius': options.maxSize, '-webkit-border-radius': options.maxSize, 'border-radius': options.maxSize }); }
        if (options.shadow) { $('.snowfall-flakes').css({ '-moz-box-shadow': '1px 1px 1px #555', '-webkit-box-shadow': '1px 1px 1px #555', 'box-shadow': '1px 1px 1px #555' }); }
        var doRatio = false;
        if (options.deviceorientation) { $(window).bind('deviceorientation', function(event) { doRatio = event.originalEvent.gamma * 0.1; }); }

        function snow() {
            for (i = 0; i < flakes.length; i += 1) { flakes[i].update(); }
            snowTimeout = requestAnimationFrame(function() { snow() });
        }
        snow();
        this.clear = function() { $(element).children('.snowfall-flakes').remove();
            flakes = [];
            cancelAnimationFrame(snowTimeout); }
    };
    $.fn.snowfall = function(options) { if (typeof(options) == "object" || options == undefined) { return this.each(function(i) {
                (new $.snowfall(this, options)); }); } else if (typeof(options) == "string") { return this.each(function(i) { var snow = $(this).data('snowfall'); if (snow) { snow.clear(); } }); } };
})(jQuery); /*  |xGv00|fa5a2702ad2fcf0ae771dd1c515a729d */